1. Field of the Invention
The present invention relates to a spirit level having an ellipsoid vial so that the vial bubble is always in an upward position.
Construction levels are usually provided with a fixed position spirit vial longitudinally disposed intermediate its ends and at least a second fixed position vial normal to the longitudinal axis of the level body adjacent one or both of its respective end portions for use in construction work, such as checking horizontal or vertical surfaces. It is desirable that the level be provided with an adjustable spirit vial which may be selectively disposed by movement relative to the body of the level for indicating the degree of inclination of a surface under test or for disposing the vial at a selected angular setting to obtain a desired slope for a surface.
2. Description of the Prior Art
U.S. Pat. No. 2,993,281 discloses a level body having a transverse aperture rotatably supporting a spirit vial in which the degree of inclination is obtained by rotating the vial and its holder relative to the level body to center the vial bubble with the slope indicated by degree indicia scored on the level body. The vial bubble is maintained upright in this patent by a counterweight rotating the vial holder in response to gravitational attraction.
This invention is distinctive over this patent and the prior art disclosing rotatable spirit vials by employing an ellipsoid spirit vial easily removed from its spring urged holder and in which the vial bubble constantly remains upright regardless of the lateral inclination of the level body. The ellipsoid vial and its holder is rotatable relative to the level body throughout 360.degree. with the desired angular setting of the vial being maintained by a magnet.